com.liangxun.yuejiula.galleryweidget.GalleryViewPager.java Source code

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Here is the source code for com.liangxun.yuejiula.galleryweidget.GalleryViewPager.java

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package com.liangxun.yuejiula.galleryweidget;/*
                                             Copyright (c) 2012 Roman Truba
                                                 
                                             Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
                                             documentation files (the "Software"), to deal in the Software without restriction, including without limitation
                                             the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
                                             permit persons to whom the Software is furnished to do so, subject to the following conditions:
                                                 
                                             The above copyright notice and this permission notice shall be included in all copies or substantial
                                             portions of the Software.
                                                 
                                             THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
                                             TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
                                             THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
                                             WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH
                                             THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
                                             */

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.PointF;
import android.os.Build;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

/**
 * This class implements method to help <b>TouchImageView</b> fling, draggin and scaling.
 */
public class GalleryViewPager extends ViewPager {

    PointF last;
    public TouchImageView mCurrentView;

    protected OnItemClickListener mOnItemClickListener;

    public GalleryViewPager(Context context) {
        super(context);
    }

    public GalleryViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @TargetApi(Build.VERSION_CODES.ECLAIR)
    private float[] handleMotionEvent(MotionEvent event) {
        try {
            switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                last = new PointF(event.getX(0), event.getY(0));
                break;
            case MotionEvent.ACTION_MOVE:
            case MotionEvent.ACTION_UP:
                PointF curr = new PointF(event.getX(0), event.getY(0));
                return new float[] { curr.x - last.x, curr.y - last.y };

            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        try {

            if ((event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_UP) {
                //super.onInterceptTouchEvent(event);

                float endX = event.getX();
                float endY = event.getY();
                if (isAClick(startX, endX, startY, endY)) {
                    if (mOnItemClickListener != null) {
                        mOnItemClickListener.onItemClicked(mCurrentView, getCurrentItem());
                    }
                } else {
                    super.onTouchEvent(event);
                }
            }

            if ((event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_DOWN) {
                startX = event.getX();
                startY = event.getY();
            }

            float[] difference = handleMotionEvent(event);

            if (mCurrentView.pagerCanScroll()) {
                return super.onTouchEvent(event);
            } else {
                if (difference != null && mCurrentView.onRightSide && difference[0] < 0) //move right
                {
                    return super.onTouchEvent(event);
                }
                if (difference != null && mCurrentView.onLeftSide && difference[0] > 0) //move left
                {
                    return super.onTouchEvent(event);
                }
                if (difference == null && (mCurrentView.onLeftSide || mCurrentView.onRightSide)) {
                    return super.onTouchEvent(event);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return false;
    }

    private float startX;
    private float startY;

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {
        try {
            if ((event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_UP) {
                float endX = event.getX();
                float endY = event.getY();
                if (isAClick(startX, endX, startY, endY)) {
                    if (mOnItemClickListener != null) {
                        mOnItemClickListener.onItemClicked(mCurrentView, getCurrentItem());
                    }
                } else {
                    super.onInterceptTouchEvent(event);
                }
            }

            if ((event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_DOWN) {
                startX = event.getX();
                startY = event.getY();
            }

            float[] difference = handleMotionEvent(event);

            if (mCurrentView.pagerCanScroll()) {
                return super.onInterceptTouchEvent(event);
            } else {
                if (difference != null && mCurrentView.onRightSide && difference[0] < 0) //move right
                {
                    return super.onInterceptTouchEvent(event);
                }
                if (difference != null && mCurrentView.onLeftSide && difference[0] > 0) //move left
                {
                    return super.onInterceptTouchEvent(event);
                }
                if (difference == null && (mCurrentView.onLeftSide || mCurrentView.onRightSide)) {
                    return super.onInterceptTouchEvent(event);
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }

    private boolean isAClick(float startX, float endX, float startY, float endY) {
        float differenceX = Math.abs(startX - endX);
        float differenceY = Math.abs(startY - endY);
        if (differenceX > CLICK_ACTION_THRESHHOLD/* =5 */ || differenceY > CLICK_ACTION_THRESHHOLD) {
            return false;
        }
        return true;
    }

    public static interface OnItemClickListener {
        public void onItemClicked(View view, int position);
    }

    private final static int CLICK_ACTION_THRESHHOLD = 5;

    public void setOnItemClickListener(OnItemClickListener listener) {
        mOnItemClickListener = listener;
    }

};